Question 1

Which of the following best describes the difference between a compound and a mixture?

Accepted Answer

A compound has a fixed composition and can only be separated by chemical means, while a mixture can be separated by physical means.

Question 2

A student is given a sample of air, a gold ring, and a glass of orange juice with pulp. Which of the following correctly classifies each sample?

Accepted Answer

Air: homogeneous mixture; Gold ring: element; Orange juice with pulp: heterogeneous mixture

Question 3

Which of the following is an example of an intensive property?

Accepted Answer

Density

Question 4

Which process is an example of a chemical change?

Accepted Answer

Burning wood

Question 5

A 50.0 g sample of a metal occupies a volume of 20.0 cm³. What is the density of the metal?

Accepted Answer

2.5 g/cm³

Question 6

Which of the following statements about allotropes is correct?

Accepted Answer

Allotropes are different physical forms of the same element.

Question 7

A chemist needs to separate a mixture of sand and salt. Which method would be most effective?

Accepted Answer

Filtration

Question 8

Which of the following best illustrates the Law of Conservation of Energy in a chemical reaction?

Accepted Answer

Energy is transferred from the system to the surroundings, but the total energy remains constant.

Question 9

How many molecules are present in 0.50 moles of water (H₂O)?

Accepted Answer

3.01 × 10²³ molecules

Question 10

Which of the following is a physical property that can be used to distinguish between ethanol and water?

Accepted Answer

Density

Question 11

A sample of oxygen gas (O₂) and ozone (O₃) are both present in a sealed container. Which statement is correct?

Accepted Answer

O₂ and O₃ are allotropes of oxygen.

Question 12

Which of the following best describes an exothermic process?

Accepted Answer

A process in which the system releases heat to the surroundings.

Question 13

A 10.0 g sample of a liquid is poured into a graduated cylinder and the volume is measured to be 12.5 mL. What is the density of the liquid?

Accepted Answer

0.80 g/mL

Question 14

Which of the following is a homogeneous mixture?

Accepted Answer

Saltwater

Question 15

Which of the following changes is NOT a physical change?

Accepted Answer

Rusting of iron

Question 16

A sample contains 3.01 × 10²³ molecules of CO₂. What is the mass of the sample? (Molar mass of CO₂ = 44.0 g/mol)

Accepted Answer

22.0 g

Question 17

Which of the following is NOT a method for separating a mixture?

Accepted Answer

Electrolysis

Question 18

Which statement about the mole concept is correct?

Accepted Answer

One mole of any substance contains 6.02 × 10²³ particles.

Question 19

Which of the following is a chemical property?

Accepted Answer

Reactivity with acid

Fundamentals of Matter and Its Classification

Study Guide - Practice Questions